Turbine blading



Sept. 22, 1925.

TURBINE BLADING Filed sept, 13, 1922 2 Sharks-811301. l

'g Q fw 56 /////y/ /v/ l INVENTOR ATTORNEY septzz, 1925.

E. ZETTERQUIST TURBINE BLADxG A- Filed sepi. 1s, 1922 2 Smets-Sham ENVENTOR ATTORNEY Patented Sept. 22, 1925.

UNITED STATES. PATENT oF FICE.

ERIC ZETTERQUIST, 0F ESSINGTON, PENNSYLVANIA, ASVSIGNOR TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A, CORPORATION 0F PENNSYLVANIA.

TURBINE BLADING.

Application filed September 13,1922. Serial No. 588,039.

To all whom t may concern:

Be it known that I, ERIC ZETTnRQUisT, a citizen of the United States, and a resident of Essington, in the county of Delaware and State of Pennsylvania, have invented a new and useful Improvement in Turbine Blading, of which the following is a specification. y

My invention relates to turbines, more particularly to the low-pressure or exhaust blading thereof, and it has for its object to provide apparatus of the character designated which shall be capable of efliciently abstracting energy from large volumes of ow-pressure motive fluid, whereby singleunit turbines of large capacity may be constructed. 4

Apparatus made in accordance with my invention is illustrated in the accompanying drawings, forming a part of this application, in which: Fig. 1 is a longitudinal sectional view of a turbine showing my improved low-pressure blading applied thereto; Fig. 2 is a fragmentary perspective view showing a portion of my improved blading; Fig. 3 is a sectional view of a single lowpressure blade taken along the line III-III of Figyl; Fig. 4 `is a detail sectional view showing a modified form of my low-pressure blading; Fig.' 5 is a sectional view taken along the line V-V of Fig. 4; and Fig. 6 is a detail view showing a further modified form of my improved blading.

In the application of Henry F. Schmidt, Serial No. 482,768, filed July 6, 1921 and in the application of Alexander T. Kasley, Serial No. 486,517, filed July 21, 1921, continued as Serial No. 521,872, filed December 12, 1921, both of which applications are assigned to the Westinghouse Electric & Manufacturing Company, there are disclosed forms of low-pressure or' exhaust turbine` blades which are capable of handling large volumes of low-pressure motive Huid elficiently. It is characteristic of the improved Y moving blades shown in these applications that motive fluid is received axially and discharged radially or radially and axially.` In accordance with my invention, blading of this general type is provided with energyabstracting portions, which are inclined with respect to the axis of rotation so that motive fluid may be discharged peripheral-ly without being turned as far as it is necessary `with the radially-discharging type,

va row of guide blades 16, carried bythe casing or cylinder 12, and a row ofV wide blade structures 17,' carried by the rotor 11.

rlhe wide blade structures 17' each include a series of sections 18 rhaving inner plane Vportions and outercurved or .spoon-outline,

energy-abstracting portions 19, which are inclined to the'turbine axis to provide conicalpaths of discharge for the motive fluid so that the latter may be discharged peripherally with a diversion from an axial path lof flow which is materially less than Plane sections 2O are interposed between the 'sections f- 18 and they are provided with shroud elements 21,V which contact to form enclosed motive fluid passages between adjacent rows of sections 18. The shroud elements 21 are preferably inclined oppositely to the energy-abstracting portions 19 sov that, whenthe blading is assembled, the tips l :present a serrated appearance with like sides of the ser-rations provided with energyabstracting'portions 19and theother like sides 'provided with shroud-s.

In Fig. 1, the last section 18 is followed by a section 22, which dischargesboth axially and peripherally. See Fig. f3. With this arrangement of blading, motive fluid is received axially and ,it is discharged peripherally bythe energy-abstracting portions 19 and axially by the axially-discharging portions of the sections 22. f

In Figs. 4and 5, I show a form of my low-pressure blading in which the entire discharge `is peripheral. The axially-discharging sections 22 are omitted and only the energy-abstracting portions 19 of the serratio-nsV are provided. However, in order to direct the motive fluid outwardly, curved deliectors" 23 are arranged between the blade structures 17.

In Fig. 6, I show a further modified form of` my low-pressure turbine stage'in `which' the moving blade structure thereof is made up of a plurality of sections 25 having wedge-shaped tips 26. Similar inclined sides 27 of the Wedge-shaped tips are shrouded by stationary 'elements 28 and 29. The portions 28 are supported in any suitable manner by the turbine cylinderycasing and the portion 29 constitutes a part of said casing or cylinder. kThe other sides of the Wedge-shaped tips 26 aie provided With curved energyfabstracting portions 30 of the spoon-'outline type, already referred to, and the last section 25 of each-blade structure is provided with an axially-discharging energy-abstracting portion 3l'.

From the foregoing, the operation of apparatus made in accordance With my invention ivillbe appa-rent. Motive fluid, s'uchas steam, is expanded andrenergy is 'abstracted in the-sections 13 and 14:` in the usual way; and, after discharge from vthe latter section.I the motive fluid then enters, the. lowpressure stage l5 for further expansion and energy abstraction.` The peripheral discharge of motive fluidA permits ofthe provision of adequatev discharge-area withv the preservation of highly efficient .discharge angles Without exceeding safe" centrifugal stresses in the material ofthe blades since the extent of discharge area is determined by the blade Width instead ofthe blade height, asis ordinarily they case. in my case is diverted materially less than 90, less energy is lost in turning the stream outwardly and more energy is available for doing' useful Work than vvould be the case if the diversion was substantially 90.

IVhile 'I have shownmy invention in but three forms, it will be obvious to thosey skilled in the art that it is not soA limited,

f but is susceptible of various other changes and modifications, without departing 'from the spirit thereof, and `I desire, therefore, that only sucli'limitations shall 'be placed thereupon as Iare imposed by the prior art or as are specifically set forth inthe appended claims. i

That I claim is:

"1. A. turbine blade comprisingia plurality of inclined energy abstractingiA porseries of inclined energysabstracting portions at the tips defining a series of' conical discharge paths for steam'. i

8. In a` turbine; a roavof moving bla-de Astructures eaclr of which comprises a'series of'outer curved energy-abstracting por- A' tionsseparated-by shrudpOrtiQns; Y

1 4.".In a turbine, a row of moving bladel structures eachfof which comprises a plurality of inclined, tip-discharging, energy Vabstractingportions followed by an axially',T discharging energy-abstracting portion,

As motive fluid tions and being serrated at the tipsv With like sides of the serrations provided With energyabstracting portions.

8. In a turbine, a rovv of moving blade structures each of which comprisesfa plurality of juxtaposed sections ivitli alternate sections having curved energy-abstractiiig portionsat the tips. v 'i 9. In a turbine,fa row of movingblade structures each ofwvhich comprisesaplurality of=juxtaposed sections with alternate sections having the tips 1inclinec'l'ivith respect to the'turbiue axis and having. curved energy-abstracting:portions at the tips. r

150. Iii-a turbine',` a row of moving blade structures each of which comprisesapluralit'yfiof Vjuxtaposed sections with kalternate vsections having curved energyabstracti-ng portionsy at the tips and A tions being shrouded. I

ll. In a turbine, a row'of moving-blade vstructures each of Vwhich comprises' a plu- .rality of pixtaposed'sections with alternate sections having the tips provided with' curved energy-abstracting portions and inclined VWith respect to the axis rof rotation and lWith the interposed sections rhaving shrouds at the tips inclined inthe opposite direction to the -axis' of rotationQ Y'- l2/In a turbine, a belt 0f exhaust blades mounted ona rotor "body and each .con'lprising a flat body porti'on'lying in si'ibstantiall a radial plane and an exiiz'iusting` 'lip yof spoon-outline having its outer surface lying at ani acute angle with the Vrotor axis,V 13. In a' turbine, a belt ofz exhaust blades mounted on thel'roto'rfbodjf'1 ladapted/'toreceive motive fluid 'in a directiony parallel y n l l to 'the rotor axis and to exhaust s aid fluid j tions at the tip separated'by shrouding and i i vdisposed laterally With respeetto each other.

2. In a turbine, a rovv of blades having a in a frusto-conical surface.

"In a turbine, "a series of vbelts ofexh'austr blades mounted 'on the' rotor "body,

each adapted to` receive/:motive fluid in`r a direction paralleli-to the' rotor axis and 'to rexhaust said fluidin a frusto-'c'onical,sur-

face fi'in`d"a series of intervening belts' 'of fluidi'etaining members, interposed therebetween` respectively and o'foppo'sed frustol vconical 'overall configuration. y

"15. lIn ifa' turbine,ya` Aseries of 'beltszi'ofex- Aliaust, blades 'mounted 'on the' rotor body, each blade comprising'a fiat body "portion disposed substantially"parallel "to, a vrotor radial plai'ieiai'id atip port-ion ofhook cross the interposed secsection, the outer' surface of which, if ex* tended, would intersect the rotor axis, whereby an exhausting surface of frustoconical shape is provided, and an opposed truste-conical fluid retaining and directing structure interposed between adjacent exhaust blade belts.

16. In a turbine, a series of belts of exhaust blades mounted on the rotor body,

each blade comprising a flat body portion disposed substantially parallel to a rotor radial plane and a tip portion of hook cross section, the outer surface of which,

if-extended, would intersect the rotor axis, whereby an exhausting surface of rustoconical shape is provided, and an opposed frusto-conical liuid retaining and directing structure interposed between adjacent exhaust blade belts, said structure being composed of a plurality of flat stem members aligning respectively with the flat body portions.

In testimony whereof, I have hereunto subscribed my name this 7th day of Sep tember 1922.

ERIC ZETTERQUIST. 

